Adjustable abutment for pistons



Aug. 5, 1952 J. E. RASOLETT] ADJUSTABLE ABUTMENT FOR PISTONS Filed Feb. 25, 1948 w w w INVENTOR. JULIUS E. RASOLETTI ATTORNEY PatentedAug. 5, 1952 UNITED V STATES PATENT OFFICE l MU2,605,748

ADJUSTABLE ABUTMENT FOR PISTONS- Julius E. Rasoletti, Cleveland Heights, Ohio, as-

signor, by; mesne assignments, to Rockwell Manufacturing Company, Pittsburgh, Pa., a corporation of Pennsylvania Application February 25, 1948, Serial No. 10,751

11 Claims.

This invention relates to devices for regulating the stroke of a work performing member, and moreparticularly to adjustable abutment means for limiting the stroke of a piston at any desired point in a cylinder.

In the operation of a tool, such as a drill,-it is often desirable that means be provided for limiting the movement of the tool toward its work. It is frequently necessary that the travel of the toolbe varied, and that there be means for indicating the travel obtained. A reciprocating piston may be employed for moving the tool or some other member, and, in order that the desired movement may be obtained, adjustable means may be provided for regulating the piston stroke. For regulating the travel of a piston carrying a tool or any other work performing member, there may be provided anabutment member in the cylinder for engagement by the piston, and manually operated means may be provided foradjusting the position of the abutment as'indicated by visible markings at the exterior of the cylinder.

: An object of my. invention is to provide improved means for limiting the travel of a piston. Another object is to provide an abutment in a cylinder for engagement by a piston, and having improved means for adjusting'its position as indicated by markings at the exterior of the cylinder. Other objects will appear in the course of the following description.

In the accompanying drawing there is shown for purposes of illustration, one formivhich my invention may assume in practice.

. In this drawing: 7

Fig. 1 is a view, partiallyin section, of a cylinder and piston having my improved adjustable abutment associated therewith. V r

. Fig. 2 is an enlarged sectional view of the adjustable abutment shown in Fig. 1. i I

Fig. 3 is a cross sectional view taken on the plane of the line 33 of Fig. 2.

. Fig. 4 is a side elevational view of the structure shown in Fig. 2. 7

Referring to the drawing it will be noted that there is shown a motor, generally designated l, of the reciprocating piston type including a cylinder 2having a bore 3 in which a piston portion 4 reciprocably received. Formed integral with the cylinder is a flange 6 which is adapted to be secured to suitable means for supporting the motor in any desired position. Fitting within the forward portion of thecylinder bore is a sleeve shaped member 8 ,whichyslidably receives a reduced portion 9 of the piston, and attached to the forward end of the cylinder isanannular member i!) into which the reduced portion 9 moves as the piston makes its forward stroke. Rotatably mounted upon a forwardly projecting flange portion I I of the annular member is a cap [2 having an opening 94 in axial alignment with the cylinder bore 2, and a further reduced piston portionl5 extends forwardly from the portion 9 through the opening l4. Formed in the flange portion l l of the annular member 10, as shown in Fig. 3, is an annular groove I6, and threaded into openings in the cap I2 are members l8 having portions l9 extending into the annular groove for holding the cap against movement longitudinally relative to the annular member. Arranged within the member It and having threaded engagement therewith is an, annular abutment member 28 surrounding the piston portion 15 and adapted to be engaged by the forward end of the piston portion 9 for limiting the stroke of the piston in aforward direction.

. In order that the abutment member may be moved to any desired position within the member I0 and thenlocked in such position, there is provided a pin 22 extending through an opening in the cap 12 and having a reduced threaded portion 23 which extends freely through an opening in a portion 24 of the abutment member and is threaded into an opening 25 in a portion 26 of the abutment member, the portions 24 and 25 being separated by a cut 28, as shown inFig. 2. It will be seen that the pin 22 connects the cap 12 and the abutment member 20 for rotation together, and that rotation of the abutment member will result in its movement longitudinally relative to the membe H? by reason of the threaded engagement between them. As the abutment member moves longitudinally within the member ID, the

pin 22 moves with it through the opening in the cap 12. In order that the operator may determine the length of the piston stroke that is obtained for any adjustment of the abutment member, markings are provided on the stem 22 tobe read at the forward face of the cap l2. The markings are so spaced that the movement of the abutment member resulting from one complete rotation of the cap 12 will be equal to the distance between adjacent markings. Formed on the cap l2 are markings 3 0 cooperating with a reference mark 3| on the member It, as shown in Fig. 4, so that the operator may determine very closely the position of the abutment member v2!]. It will be appreciated that the visible marking on the pin 22 nearest tothe cap 12 plus the marking on t e ca I pposite theref n k 3' will give the length of the piston stroke permitted by the abutment member.

After the abutment member has been moved to the desired position, it may be locked in place by rotating the pin 22 about its own axis to effect a clamping of the abutment portions 24 and 26 on the threads 'of the member Hi. It will be seen that the shoulder formed on the pin 22 by the reduced portion 23 engages the forward face of the abutment member, and the portion 23 threaded only into the opening tends to move the abutment portion 25 toward the portion'24 when the pin is rotated in aclamping direction. Formed in the outer end of the-pin is a groove 32 for receiving an instrument, such as a screw driver, to rotate the pin in the desired direction. It will be appreciated that only a very slight rota-- tion of the pin will be needed to obtain a clamping or releasing of the threads.

The piston 4 is shown herein carrying a chuck 34 adapted to support a tool, not shown, such as a drill. The chuck is fixed to a spindle 35 which extends axially through the piston and is rotatably supported by bearings, one of which is shown at '38. Shoulders 3! on the spindle engage the bearing races for holding it against long-itudinal movement relative to the piston. The rear portion of the spindle 35' has a splined connection, as shown at 38, to the power shaft 39 of a motor 40 mounted upon a rear cylinder head 4i. A piston portion 42 extends rearwardly from the piston portion 4 and is slidably received withina bore 43' formed in the rear cylinder head. The piston portion 42 is suitably bored to receive the power shaft 39 as the piston is moved rearwardly in the cylinder. Arranged on the piston portions '4, 9 and 42 are packing ring-s 44, 44' and 44" sealingly engaging the walls of their respective cylinder bores.

For efiecting reciprocation of the piston, there are provided pass-age means 45 and 4B communicating with opposite ends of the cylinder bore 3. Suitable valve means, not shown, may be provided for connecting the passage means 45 and 4B selectively to pressure fluid supply and exhaust.

To perform a drilling operation, the abutment member 20 is first adjusted by rotating the cap 12 manually until the markings on the pin 22 and the 'cap indicate that the desired forward movement of the motor piston will be obtained. The pin 22 is then rotated to clamp the threads of the abutment portions on the threads of the member 1'0 and effect a locking of the abutment member in place. The opposite sides of the piston portion 4 are then connected topressure fluid supply and exhaust in a'manner to effect reciprocation of the piston while the motor 40 is operated to rotate the spindle 35.

While there is disclosed in this application one form which-my invention may assume in practice, it ;will be understood that it may be modified and embodied in various other forms without departing from the spirit orthe scope of the appended claims.

What I claim as new, and desire to secure by Letter's Patent or the United Stateais: I

""1. 'A'n adjustable abutment for apiston reciprocating in a cylinder comprising, 'in co'n'ribina' tion, a 'cylindricalbody fixed to one end of said oylinder-andhaving a bore for receiving' an end portion of -said piston, an abutment member re- 'ceived within said here ro'r engagement by said piston "to lim-it its travel in one direction, said abutment member having tlireaded engagement with the walls of said bore, and means for-adjusting the position of said abutment member including a member mounted for rotation relative to said cylindrical body about an axis coinciding with the axis of said bore and means interconnecting said abutment member and said rotatably mounted member for rotation together comprising' a pin connected to one of said members and extending through an opening in the other of said members.

2. An adjustableabutment for a piston reciprocating in a cylinder comprising, in combination, an annular member fixed to one end of the cylinder and adapted to receive an end por- "tion of saidpiston; an abutment member for said piston received within said annular member and having threaded engagement with the walls of the latter, a cap rotatably mounted upon said annular member, and rotary motion transmitting means interconnecting said cap and said abutment member and adapted to permit relative axial movement therebetween' whereby said abutmentmember is caused to rotate in response: to rotation of 'saidcap and move axially with respect to said cylinder to vary the relative-axial relationship between said cylinder and saidabutment member. 7

3. adjustable abutme'nt'for a'pi-ston reciprocating 'in a cylinder comprising, in combination, anannular member fixed to one end of said cylinder'and adapted to receive an end portion of said piston, an abutment member received with-in said annular member and engageable by said piston, said abutment member having threadedengagement with the walls of said annularmejmber, a 'cap rotatably mounted upon saidannular member, means for holding said cap against movement longitudinally of saidannular member, anda pin fixed to said abutment member ata point spaced radially from the axis of said annular member and extending forwardly throughan opening in said cap for connecting said abutment member and said cap for rotation together while permitting bodily movement of said abutment member relative to said cap.

4. 'Ihe-adjust-able abutment of claim 3 in which markings are provideddnsaid pin and cap for indicating'theposition of said abutment member.

5. The adjustable abutment of claim 3 in which a cut is made in said abutment member toiorm se'p'arate abutment portions, and said pin is provided with a reduced portion extending through an opening in one abutment portion and threaded into an opening in the other abutmerit portion wherebya rotation of said pineffec'ts a clamping of the threads-on said abutment member in engagement with the threads on said annularmember for eifectinga locking of said abutment member in place.

6. An 'adjustable abutment for a piston reciprocating in a cylinder'andhavin'g a portion extending through one end-of the cylinder for-supporting a working tool comprising, in combination bylindri'c'al member-fixed to the' forward end of said cylinderfi-an annular abutment membei' receivedWithin said cylindrical niember surrounding theiforward portion of said piston and engageabie by' 'a'h fend surfac'e of thelatter, s'aid abutment fmemb er-having threaded engagement withl-said- "-'cylindrical "member, *a cap rotatably mounted upon said cylindrical member, means for hoiding said cap against movement longitudinally' relative tosaid cylindrical member, :a cut formed through a 'p'ortion er said abutment memer between its ends, and ,1 a :pin engaging crtions of said abutment member at opposite sides of said out and adapted for rotation to effect relative movement of the portions separated by the out, said pin extending forwardly through an opening in said cap and connecting said abutment member and cap for rotation together.

7. An adjustable abutment for a piston reciprocating in a cylinder comprising, in combination, an annular member fixed to one end of the cylinder and adapted to receive an end portion of said piston, an abutment member received Within said annular member for engagement by said piston to limit its travel in one direction, said abutment member having threaded engagement with the walls of said annular member, a cap rotatably mounted upon said annular member, means for holding said cap against movement longitudinally of said annular member, and mean connecting said cap and said abutment member for rotation together while permitting bodily movement of said abutment member relative to said cap con prising a pin connected to said abutment member and extending through an opening in said cap at the forward end of said annular member.

8. An adjustable abutment for a piston reciprocating in a cylinder comprising, in combination, a cylindrical body fixed to one end of said cylinder and having a bore for receiving an end portion of said piston; an abutment member received within said bore for engagement by said piston to limit its travel in one direction, said abutment member having threaded engagement with the walls of said bore; means for adjusting the position of said abutment member including a member mounted for rotation relative to said cylindrical body about an axis coinciding with the axis of said bore and means interconnecting said abutment member and said rotatably mounted member for rotation together comprising a pin connected to one of said members and extending through an opening in the other of said members; and locking means operable to prevent relative movement between said abutment membar and cylindrical body.

9. An adjustable abutment for a piston reciprocating in a cylinder comprising, in combination, an annular member fixed to one end of the cylinder and adapted to receive an end portion of said piston, an abutment member received within said annular member for engagement by said piston to limit its travel in one direction, said abutment member having threaded engagement with the walls of said annular member, a cap rotatably mounted upon said annular member, means for holding said cap against movement longitudinally of said annular member, and means inter connecting said cap and said abutment member for rotation together including a pin operatively interconnecting said cap and said abutment member to transmit rotary motion from the former to the latter while permitting longitudinally relative movement therebetween.

10. In a hydro-pneumatic power feed assembly comprising a power feed cylinder having ringlike end closure heads each providing a tubular body having a through bore adapted to operatively receive a piston member designed for limited reciprocation and a piston member having an external piston adapted for sealed sliding engagement with the bore of said cylinder, and axial extension of reduced diameter extending from each of the end faces of said piston portion and adapted for sealed sliding engagement with the bores of the respective cylinder and closure heads, one of said axial extensions terminating in an extension portion of further reduced diameter; an adjustable reciprocation limiting mechanism comprising a tubular extension on the one of said closure heads receiving said one of said axial extensions and extending in axial, surrounding, radially spaced relation to said extension portion to provide an annular open ended space and being provided with internal threads; and an externally threaded abutment member threaded into said annular space to a predetermined set position whereby, upon reciprocation of said piston in one direction, the end face of one of said axial extensions will contact said abutment member to limit the movement of said piston memher to the desired length of stroke.

11. The combination defined in claim 10, including a cap member rotatably mounted on said extension of said head portion, said cap member having an axial bore in its radial wall surrounding the external wall of said extension portion and being mechanically connected to'said abutment member to transmit rotary motion from the former to the latter while permitting relative axial movement therebetween.

JULIUS E. RASGLETTI.

REFERENCES (JITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 631,698 Cowles Aug. 22, 1899 997,648 Cavanagh July 11, 1911 2,213,026 Hoffman Aug. 27, 19 10 2,305,302 Mazur Dec. 15, 1942 2,340,735 Claus Feb. 1, 19 14 2,397,106 Haller Mar. 26, 1946 

